Telephone handset



Aug. 28, 1934.

H. F. OBERG FELL TELEPHONE HANDSET Filed May 12, 1932 EI'H all Patented Aug. 1934 TELEPHONE HANDSET Herbert F. Obergfell. River Forest, 111., assignor to Associated Electric Laboratories, Inc., Chi-- cago', 111., a corporation of Delaware Application May 12, 1932, Serial No. 610,895

7 Claims. (CL 174-403) This invention relates to improvements in handset combinations for use in telephone instruments. As is well-known these handset combinations comprise a handle portion having "a receiver incorporated in one end and a transmitter in the other end so that when the handset is in use the receiver is-brought to the ear and the transmitteradjacent the mouth of the user, and the principal object of the invention resides in the design of a handset in which neatness and economical manufacture, together with durabilinsuring that the opening in the mouthpiece comes directly opposite the mouth of the user. In accordance with this object a particular feature of the invention resides in a novel transmitter mouthpiece which-does not require mounting in a particular position and in which the sound waves can enter it from any angle.

A further feature of the invention is concerned erably made of bakelite. having a handle portion so that it may be taken hold of by a person using this device. There is an enlarged opening 'or casing on each end of the handle, in one of which any well known receiver unit 6 is ,placed and held in position by the round ear piece 7 which is screwed'down over the opening in the handle 5. The transmitter unit 8 is supported in the open-, ing in the other end of the handle 5 and held in .place by the circular mouthpiece 9 having a number of radial slots 10 cut into itfor the entrance of the sound waves. The mouthpiece 9 is clamped on the front side of the transmitter unit 8 and the opening of the handset 5 by means of the metal ring 11' threaded on the outside of the opening in the handset. The mouthpiece 9 being circularin shape and having the openings 10 arranged cireumferentially and evenly spaced I around its surface does not require any particular set position with regard to the transmitter unit and the mouth of the person using the device. It may be turned axially to any position in sis-- ,sembling it and the metal ring 11 screwed down tight. The sound waves will enter the openings 10 from any direction. The transmitter unit 8 has a flange 12 formed on it extending around its periphery against the front side of which the mouthpiece 9 presses when inplace.

with a transmitter unit which is secured in the be apparent hereinafter in the detailed descrip-.

tion which, together with the drawing, relate to a preferredembodiment "of the invention.

In the drawing, Fig. lshows a side cross-sectional elevation of a complete handset unit with the transmitter and receiver units shown in full lines; Fig. 2 is a view of a well-known standard type of'transmitter unit and associated mouthpiece shown in the handset of Fig. 1 toindicat'e the-interchangeability of the difl'erent types of transmitter units; Fig. 3 shows a full front. elevation of the transmitterend of the handset with the transmitter unit removed; Fig. 41s a perspective elevation of one of the arcuate metal plates 55 for supporting the transmitter unit} while, Fig. 5 is a diagrammatic illustrationcof the circuit connections extending to the various terminal points in the handset. a f Referring now moreparticularly to Fig. 1, the I) handset comprises a single moulded unit 5, pref- A pain of arcuate shaped metal plates 16 and 17 are'supported on opposite sides of the bottom of the opening in the handset 5 by means of a pair of integral ears 18 which are engaged by the mounting screws 19 threaded into shoulders formed or moulded in theibottom of the-opening; The openings adjacent the ears 18 in the plates permit a screw driver to turn the screws 19 into position. The screws 19 in addition to holding the arcuate metal'plates 16 and 1'7 in the opening serve as terminal screws for the attachment of the connecting wires. The flange or shoulder 12 on the transmitter unit 8 abuts the top edge of the metal plates 16 and 17 when the mouthpiece 9 is screwed down by the metal b d 11 against .the front side of the shoulder 12. The transmitter unit 8 is, thereby securely held in its position in the opening of the" handsetI An electrode at the bottom of the center of the trans- .mitter unit 8 has a projection 20 extending outwardly therefrom which engages a flexible leaf" spring 21 secured by the terminal screw 22 in the no bottom of the casing. The arcuate metal plates 16 and P1 in addition to buttingup against the flange 12 of the transmitter 8v frictionally engage the sides of the transmitter unit, due to their resiliency. k

It will be noted that the transmitter unit 8 hasno external protruding terminal screws or binding posts for the attachment of the connecting wires. In order to provide for connections tothe transmitter 8, advantage is taken of the 129 moulded bakelite which-is inherently of insulat- "ing" property. In the arrangement disclosed in through the receiver unit 6 to the flexible leaf spring 21 which in turn bears against the shank 20 or the rear electrode and this in turn,'in the well-known manner, extends the current through the carbon granules and then to the front electrode. The front electrode is directly connected in any suitable manner to the metal casing or container which encloses the transmitter 8. The. circuit of the-current. path then extends from the outside surface of the transmitter 8 to one or the other of the arcuate metal plates 16 or 17 with which the unit is in engagement and out to the line wires. The terminal screws 19 in addition to supporting the plates 16 and 17 by the ears 18 secure the connecting wires thereto. An opening 35 in the transmitter end 01 the handset 5 permitsentrance of the connectinghandle portion'5 of the handset including the opening of the transmitter casing is of exactly the same construction as that shown in Fig. 1. The transmitter unit 32, however, is of a different type of construction from that of the transmitter 8 of Fig. 1 in that the connecting terminals for the attachment of the electrical conductors are mounted directly on to the rear of the transmitter unit. Additional connecting wires between the terminals 19 in the bottom of the casing of the handset 5 must, therefore, be provided for connecting with the terminals on the rear side of the transmitter unit.. Because ofthe position of the terminal connecting screws on the rear of the transmitter unit 32 this unit mustbe set in a certain particular position. In the opening of the casing of the handset 5 so that it cannot be rotated as the transmitter unit 8 of Fig. 1 can be rotated axially. For this purp se a keyway on the rear side of one p0 t of the ansmitter s2 is engaged by a raised portion 34 in the periphery of the casing of the handset opening and looks it in position. r

The mouthpiece 30 containing sound openings 31 is of a slightly difierent construction from the mouthpiece 9 of Fig. 1. It must be mounted on the handset in a particular position so that sound waves can enter its openings from only a certain direction and for this reason it must be secured so that it cannot be rotated axially. For this purpose suitable lugs on opposite sides of the rear of the mouthpiece 30 engage slots 33 on opposite sides of the periphery of the transmitter unit 32. The metal ring 11 which is the same as the metal ring 11 of Fig. 1 clamps on the outside of the easing of the handset 5 and holds the mouthpiece 30 directly on the front side of the transmitter 32 which in turn rests on the edge of the opening in the handset.

It will be seen that by merely inserting the arcuate metal plates 16 and 17 into the bottom of the casing and using the screws 19 to hold them in place, the transmitter unit 8 of Fig. 1

together with its mouthpiece 9 may be substituted in place of the transmitter 32 mouthmitter unit.

fact that the handset unit 5 is constructed of piece 30. This renders it unnecessary to pro vide two different kinds of handlesfi and their openings on each end for difierent kinds of transmitter units and their associated mouthpieces. The handle may then be said to be of universal construction.

' What is claimed is:

1. In a transmitter casing, a transmitter unit therein,-a pair of arcuate shaped members in said casing resiliently engaging opposite sides of said transmitter unit to support the transmitter in position, means for securing said members in said casing and at thesame time terminating connecting wires thereto, said members extending electrical connections between said transmitter unit and said connecting wires.

2. In a transmitter casing, a transmitter unit therein, arcuate metal plates resiliently engaging opposite sides of said transmitter unit to support it in said casing and to complete electrical circuits thereto, and mounting screws for fastening said metal plates in said casing and for securing-connecting wires thereto.

3. In a transmitter casing, a transmitter unit therein, arcuate plates fastened to said casing and resiliently engaging opposite sides or" said transmitter unit to support, it in position said plates serving to carry current to said transmitter, a mouthpiece for said transmitter, and means for clamping said transmitter between said mouthpiece and said arcuate plates.

4. In a transmitter casing; a transmitter unit therein, arcuate metal plates secured in said casing and irictionally engaging opposite sides of the transmitter unit, said plates supporting said transmitter in said casing and extending electrical connections thereto, a mouthpiece for said transmitter unit, and means for securing said mouthpiece to said casing so that it also holds said transmitter unit against theiedges of said metal plates.

5. In a transmitter casing, a pair of transmitter units, one or theother of said units adapted to be placed in said casing, said first unit having electrical connections made to it previously to its placement in said casing, said other unit having electrical connections made to it consequent to its placement in said casing, and an adapter member in said casing in case said other unit is placed therein, establishing electrical connection therewith and securing the unit therein.

6. In a transmitter casing, a transmitter. unit in said casing, said transmitter unit having notches on opposite .sides of its periphery, a mouth piece covering the front of said transmitter unit and having lugs on opposite sides of its periphery engaging the notches in said transmitter unit h) prevent axial rotation of the mouth sii piece/and a clamping ring threaded onto said casing clamping said mouthpiece to said trans- '1.'In a transmitter casing, a transmitter unit in said casing, a keyway at one edge of the rear of said transmitter unit, 9. lug in the periphery of said casing engaging said keyway in said unit to prevent axial rotation of the transmitter with respect to said casing, said transmitter unit having notches on opposite sides of its front surface,

a. mouthpiece covering the front of said transmitter and having lugs on opposite sides of its rear engaging the notchesin said transmitter to prevent axial rotation of the mouthpiece with respect to said transmitter, and a clamping ring threaded onto said casing to clamp said mouthpiece and transmitter unit together to said casin :II-I' in F. OBERGFEIL. 

